Body Weight as a Preferred Method for Normalizing the Computed Tomography-Derived Liver Volume in Dogs without...

Area of Science:

• Veterinary Radiology and Imaging
• Comparative Veterinary Medicine
• Diagnostic Imaging

Background:

• Radiography for liver size assessment in dogs is limited by patient variability, hindering accurate hepatomegaly or microhepatia diagnosis.
• Computed tomographic (CT) volumetry offers quantitative liver volume measurement but lacks established normalization methods in healthy dogs.
• Accurate liver volume assessment is crucial for diagnosing hepatic conditions in canine patients.

Purpose of the Study:

• To evaluate seven anatomical measures for normalizing liver volume in dogs using CT.
• To establish tentative reference ranges for liver volume in healthy dogs.
• To identify the most reliable method for standardizing liver volume measurements via CT.

Main Methods:

• Retrospective analysis of abdominal CT scans from 41 dogs without hepatic disease (January 2017-June 2020).
• Recorded liver volume, vertebral lengths (T11-T12, L2-L3), abdominal aorta diameter, body weight, and body condition scores (BCSs).
• Assessed seven different anatomical measures for normalizing CT-derived liver volume.

Main Results:

• The mean CT-derived liver volume was 813.8 ± 326.5 cm³.
• Body weight emerged as the most reliable single variable for normalizing liver volume.
• A regression model (volume = 19 × BWkg + 97) and a liver-volume-to-body-weight ratio (22.1 cm³/kg) were established.

Conclusions:

• Body weight is a practical and reliable factor for normalizing liver volume in dogs assessed by CT.
• Fat-free mass may offer superior normalization but requires accurate measurement.
• This study provides a basis for standardized CT-based liver volume assessment in veterinary diagnostics.